LED Blinking Patterns

Solving Approach

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Code

// Define the pins for the LEDs and the push button switch
const int led1 = 8;
const int led2 = 9;
const int led3 = 10;
const int led4 = 11;
const int buttonPin = 2;

// Variables to manage the pattern state
int currentPattern = 1;

// Variables to handle button press detection
int buttonState;
int lastButtonState = HIGH;
unsigned long lastDebounceTime = 0;
const long debounceDelay = 10;

// Variables for non-blocking LED timing
unsigned long lastBlinkTime = 0;
int ledState = LOW;

void setup() {
  // Set LED pins as outputs
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  
  // Set button pin as input with an internal pull-up resistor
  pinMode(buttonPin, INPUT_PULLUP);
  
  // Initialize Serial Monitor
  Serial.begin(9600);
}

void loop() {
  // Read the state of the button
  int reading = digitalRead(buttonPin);

  // Check for button state change
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }

  // If enough time has passed, update the button state
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;
      // If the state is LOW, a button press has occurred
      if (buttonState == LOW) {
        currentPattern++;
        if (currentPattern > 5) {
          currentPattern = 1;
        }
      }
    }
  }

  // Update the last button state
  lastButtonState = reading;

  // Execute the pattern based on the currentPattern
  switch (currentPattern) {
    case 1:
      // Pattern 1: All 4 LEDs blink together
      if (millis() - lastBlinkTime > 500) {
        lastBlinkTime = millis();
        ledState = !ledState;
        digitalWrite(led1, ledState);
        digitalWrite(led2, ledState);
        digitalWrite(led3, ledState);
        digitalWrite(led4, ledState);
      }
      break;

    case 2:
      // Pattern 2: LED 1 & 3 blink, then 2 & 4
      if (millis() - lastBlinkTime > 500) {
        lastBlinkTime = millis();
        ledState = !ledState;
        digitalWrite(led1, ledState);
        digitalWrite(led3, ledState);
        digitalWrite(led2, !ledState);
        digitalWrite(led4, !ledState);
      }
      break;

    case 3:
      // Pattern 3: Sequential blink
      if (millis() - lastBlinkTime > 250) {
        lastBlinkTime = millis();
        digitalWrite(led1, LOW);
        digitalWrite(led2, LOW);
        digitalWrite(led3, LOW);
        digitalWrite(led4, LOW);
        
        switch ((millis() / 250) % 4) {
          case 0:
            digitalWrite(led1, HIGH);
            break;
          case 1:
            digitalWrite(led2, HIGH);
            break;
          case 2:
            digitalWrite(led3, HIGH);
            break;
          case 3:
            digitalWrite(led4, HIGH);
            break;
        }
      }
      break;

    case 4:
      // Pattern 4: LED 1 & 2 blink, then 3 & 4
      if (millis() - lastBlinkTime > 500) {
        lastBlinkTime = millis();
        ledState = !ledState;
        digitalWrite(led1, ledState);
        digitalWrite(led2, ledState);
        digitalWrite(led3, !ledState);
        digitalWrite(led4, !ledState);
      }
      break;

    case 5:
      // Pattern 5: LED 1 & 4 blink, then 2 & 3
      if (millis() - lastBlinkTime > 500) {
        lastBlinkTime = millis();
        ledState = !ledState;
        digitalWrite(led1, ledState);
        digitalWrite(led4, ledState);
        digitalWrite(led2, !ledState);
        digitalWrite(led3, !ledState);
      }
      break;
  }
}

Output

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